Actions of users (or panelists) participating in a research panel may be correlated with demographic information for the users, which in turn may be extrapolated and applied to a general population. For example, websites that users in an Internet research panel visit may be associated with demographic information for the users. This demographic information may be used to determine a likelihood that a particular user having particular demographic characteristics will view a particular website, will click on a particular advertisement displayed on the particular website, and/or will purchase products and/or services related to the particular advertisement displayed on the particular website. Improved techniques for tracking websites or Internet locations that a user in an Internet research panel has visited, which are not burdensome to the user, are needed.